Watch Live: SpaceX’s Dragon Capsule Blasts Off to Space Station

Watch live as SpaceX’s Dragon capsule launches on its illustrious return to the International Space Station, with coverage from NASA starting at 4 p.m. Pacific/7 p.m. Eastern. Blast off is scheduled for 5:35 p.m. Pacific/8:35 p.m Eastern.

Following its spectacularly successful demonstration flight in May, the Dragon spacecraft will be docking once again with the ISS and this time, it will actually be doing something. SpaceX’s capsule is bringing 1,000 pounds of supplies to astronauts aboard the station, including 23 scientific experiments designed by students. After 18 days mated to the ISS, Dragon will return to Earth with more than 1,200 pounds of research equipment and supplies.

The launch represents a new strategy for NASA, which is expected to rely on private spaceflight companies to bring future materials and equipment to the station. SpaceX is also working to convince NASA that its spacecraft are safe enough to bring astronauts up and down from the ISS — the agency currently relies on Russian hardware. SpaceX hopes to be rated for human spaceflight by 2015.

As SpaceX and its founder Elon Musk are quick to remind people, there are still many things that can go wrong with a nascent space operation. Just before the May flight, Dragon’s launch had to be scrubbed one second before liftoff because of a small mechanical failure.